"In my view it's not so much winning and losing or even the people themselves, the president and myself - it's about something bigger than that," Romney told a cheering crowd of thousands.

The Republican's campaign has been counting on the debates with the president to set Romney on a path to winning the presidency. Romney spent more than eight days in September holding mock debates, poring over policy briefing books and sparring with Ohio Sen. Rob Portman, who stood in for Obama.

Meantime, the Obama campaign is stepping up criticism of Romney's past investments in China.

In a new television ad, the campaign accuses the Republican nominee of investing in a company that maximized profits by paying Chinese workers "next to nothing" to manufacture appliances. The ad aims to discredit Romney's assertion that he would take on China's trade advantage over the U.S.

China has emerged as a key economic issue in the election. Romney is running ads saying Obama has been too soft on China and let U.S. jobs move overseas. Both campaigns see the issue as an appeal to undecided working-class voters.

The ad is running in New Hampshire, Virginia, Florida, Ohio, Iowa, Colorado and Nevada.

(Copyright 2012 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)